1. Field of the Invention
The present invention relates to passivation layers for packaged dies and methods for forming the same.
2. Description of the Related Art
Die carriers are used in the construction of integrated circuit chips or dies to connect such dies to larger circuits, such as the motherboard of personal computers. In the past, die carriers, such as lead frames, have been most commonly metal. After mounting the die of the die carrier and connecting the leads, passivation layers are generally formed over the mounted die and carrier to protect the chips from moisture, chemicals, and other environmental factors.
Passivation layers can be formed on lead frames using chemical-vapor deposition and thermal processes at relatively high temperatures, due to the high melting point of the metal. Recently, however, plastic has become more widely used in die carriers. Due to the low melting point of plastics, such die carriers are easily damaged by exposure to high temperature steps.
Consequently, there is a need for a process for forming a protective layer on integrated circuit devices and other surface mounted structures at lower temperatures. Desirably, the passivation layers formed by the process should be moisture resistant and protect the underlying die.